Zero turn radius utility vehicles exist today in a wide variety of forms and types with lawnmowers being among the most popular. Typically, the prime mover for a zero turn radius lawnmower consists of an internal combustion engine. The output from the internal combustion engine is then coupled to one or more pulleys and/or a direct shaft link, for turning at least two different drive systems that are driven by the rotary output of the engine.
The first drive system is usually a pulley, or a direct shaft link, that drives a tool, such as a blade system that turns the blades of the lawnmower. Other tools driven by the tool driver include snow blowers, tillers, winches and the like that can be driven by the tool driver that is powered by the internal combustion engine.
The second drive system is usually a pulley, or a direct shaft link, that drives a propulsion system, such as a variable speed drive (e.g. hydrostatic, toroidal, friction, CVT or the like) or the generator/alternator of a hybrid propulsion system.
Hydrostatic zero turn propulsion systems are known, including at least two outputs of a transmission or pair of transmissions that are independently controllable with respect to each other. By independently controlling the first and second transmission outputs, one can control the operation of the first and second driven wheels.
Although such propulsion systems for zero turn radius vehicles perform their function in a workmanlike manner and provide the basis for operation of a wide variety of highly functional and well received products on the market, room for improvement exists. In particular, room for improvement exists in being able to provide a propulsion system for a lawnmower that is more energy efficient. One way in which such efficiency can be achieved is through the use of a hybrid propulsion system.
Hybrid propulsion systems and components therefor that are useable with lawnmowers are described in U.S. patent application Ser. No. 14/918,465, filed on Oct. 20, 2015, the terms of which are incorporated fully herein by reference.
The hybrid propulsion system of the present disclosure preferably comprises an internal combustion engine whose primary purpose is to rotate a generator/alternator to thereby generate electricity. The electricity so generated is stored in one or more storage batteries. Electricity from the storage batteries is then directed to one or more electric motors. The electric motors are operatively coupled to the driven wheels so that the rotation of the motor rotates the driven wheels. In such systems a gear reduction assembly can be provided to reduce the speed of the rotary output of an electric motor to a rotary output speed that is suitable for use in connection with the lawnmower.
One benefit of such a propulsion system is that it has the potential to be more energy efficient than straight internal combustion driven power systems. Another benefit is that it has the potential to simplify the design of the vehicle by employing electronic controls in place of complex levers and linkages.
One difficulty encountered with a use of a plurality of electrical controls and electrically actuated components relates to operatively coupling the various components and systems together. Coupling is necessary both for facilitating communication between the components and to provide a power source for those components that may require power to operate.
One way to provide power and communication between the various components is to couple the components together by hard wiring with conductors of appropriate gauges. Hard wiring is usually more reliable and cost-effective than wireless communications. Additionally, although communication signals can be easily transferred between components via a radio or wireless communication, it is often difficult to conduct power between components by any means other than the use of a wire conductor.
One of the difficulties with wiring components together relates to the number of wires that must be employed to handle the myriad of components that are employed for modem devices. Even allegedly “simple” devices such as zero turn radius lawnmowers can include a plurality of components that require a large number of wires being strung between components. The wiring necessary to appropriately serve all of the components has the distinct potential to create the need for large wiring harnesses that may be difficult to install correctly during the manufacture of a device. As such, one object of the present disclosure is to provide a wiring system with reduced complexity.
Another issue that arises for designers and manufacturers of utility vehicles is designing such vehicles to be flexible enough to be able to accept additional, improved and newly developed electronic components. These may include electronic components such as global positioning devices, inertial measurement units, temperature sensors, tachometers, processors and the like. Other examples may include processors that control the operation of the device to automatically “drive it,” by controlling the speed and direction of movement of the electrical motors, along with processors that may communicate with all of the various sensors, GPS devices and other electronic components on the utility vehicle to transmit real time data relating to the operation of the vehicle via a phone or Wi-Fi link to a remote management or command center.
Another desirable feature of such a wiring system would be the ability of a system to quickly and easily adopt and be operatively coupled to a newly added or different controller.
In some embodiments, a “master controller” may not be a required component of the utility device, as each of the individual components may include enough processing power to handle the functions that the particular component must perform, along with communicating with other components of the utility vehicle so that the vehicle can perform all of its intended functions. However, in other situations, a master controller may be utilized to control one or more components, and may, from time to time, need to be upgraded to incorporate additional functionalities, or to enhance the performance of the controller by performing software upgrades and the like.
As such, one object of the present disclosure is to provide an electronic control system that has the flexibility to incorporate a wide variety of existing components, sensors and other devices requiring an electrical power or communication capability (collectively, “add on devices”) that exist now, and that may exist in the future.
Known lawn-tractor type utility vehicles include a plurality of analog sensors which may include, among other things, an operator presence sensor, a parking brake sensor, a power take-off engagement sensor, and a transmission neutral sensor. Outputs from these sensors are typically fed into a bank of relays which utilizes simple ladder logic to make determinations such as whether the vehicle engine can be started or whether the vehicle engine must be shut off during operation.
For example, if an operator presence sensor detects an operator is sitting in a seat, a parking brake sensor detects engagement of the parking brake, and a power take-off sensor detects the power take-off is turned off the relays will be in a state such that the engine will be allowed to start. However, if an operator presence is detected, the parking brake is detected as being engaged, but the power take-off is in an on state then the engine will not be permitted to start. As another example, if the parking brake sensor detects that the parking brake is disengaged (e.g. the vehicle is being driven), and the operator presence sensor detects an operator is not present (e.g. the driver stands up) then a kill signal will be sent to the engine. Therefore, various combinations of sensor detection will permit the engine to start, prevent the engine from starting, or kill the engine.
There has been a recent trend to incorporate various electronic components into lawn tractor-type vehicles for which operation by digital controllers is desired. For example, in a hybrid-type lawn vehicle, digital controllers are utilized to control one or more electric motors and a generator. To incorporate these digital controllers into such a vehicle, some manufacturers replace the aforementioned analog sensors with digital sensors. However, digital sensors are typically more expensive than their analog counterparts and can require very complex wiring systems. Additionally, in some instances the use of digital sensors can require a partial vehicle redesign. Therefore, it would be desirable to incorporate the analog sensors and digital controllers in such a vehicle in a less complex and cost effective manner.
In addition, these controllers may be programmable and therefore allow for a great degree of flexibility. A programmable controller can allow the user to set and alter various parameters of the vehicle that can affect the performance characteristics of the vehicle. However, the incorporation of such controllers can result in a very complicated electronic control and communication system.
Lawnmower vendors, original equipment manufacturers, and repair technicians desire a simple way to troubleshoot, repair, and/or setup the electronic system. Presently a technician will plug in a custom manufactured programming device or laptop computer to perform programming changes. However, both custom programming devices and laptops require a substantial initial investment in equipment and software and often require significant training to operate.
One potential solution would be to incorporate an onboard input device, having a screen, keypad, and necessary software, into the vehicle. However, utility vehicles are subjected to harsh environmental and operating conditions such as large temperature swings, wet weather, and bumps; therefore, any onboard input device would need to be very rugged. This dedicated onboard input device, especially with a highly robust and rugged construction, would add substantial cost to the vehicle and may not be seen as a “value added” feature to many consumers.
Therefore, it would be desirable to have a system which can troubleshoot, setup, and/or repair the aforementioned controllers, which requires little skill to operate, is highly portable, and which requires minimum cost. Therefore, further technological developments are desirable in this area.